Mobile ion transport pathways in (LiBr) x[(Li 2O) 0.6(P 2O 5) 0.4] (1-x) glasses

Abstract

(LiBr) x[(Li 2O) 0.6(P 2O 5) 0.4] (1-x) glasses with 0≤ x≤0.2 are prepared by melt quenching. Glass transition temperature (T g), ionic conductivity (σ), and its activation energy (E a) are determined experimentally and correlated to molecular dynamics (MD) simulations with an optimized potential, fitted to match bond lengths, coordination numbers, and ionic conductivity. Based on equilibrated MD configurations, ion transport pathways are modelled in detail by the bond valence approach to clarify the influence of the halide dopant concentration on the glass structure and its consequence for Li ion mobility. Results of experimental and computational studies are compared with our previous report on the (LiCl) x[(Li 2O) 0.6(P 2O 5) 0.4] (1-x) system. Both T g and σ values are higher for LiBr-doped glasses than for LiCl-doped glasses, but the effect of halide doping is unusually small. © Springer-Verlag 2010.